PRODUCTION OF POLYOLEFINIC RESIN FOAM

摘要

PURPOSE:To obtain a polyolefinic resin foam having uniform and fine cells and a high ratio of closed cells expanded in high magnification by using an inexpensive inorganic gas free from environmental problems as a blowing agent. CONSTITUTION:100 pts.wt. of a polyolefinic resin (polyethylene or polypropylene) is mixed with an inorganic foam nucleus forming agent (talc) subjected to surface treatment with a coupling agent (silane-based coupling agent) to prepare a resin composition. The resin composition is fed to a vented extruder, melted and kneaded, an inorganic gas (carbon dioxide gas) is introduced under pressure as a blowing agent from the vent part of the extruder and the melted material is extruded and expanded from an extrusion spinneret to give the objective polyolefinic resin foam.